The optimization of experimental parameters in the biogas production by anaerobic co-digestion of regional animal wastes (cow and chiken manure), municipal water treatment plant sludge and municipal landfill leacheate via microwave pre-treatment

One of these renewable energy sources is biogas which is the result of anaerobic digestion of organic substances. Wastes like regional animal wastes (cow manure and chicken manure), municipal water treatment plant sludge and municipal landfill leachate were made into a mixture according to the literature taking into account parameters (pH, temperature, hydraulic retention time, organic loading rate, alkalinity and volatility fatty acids). The mixture in the reactor (type of batch digestion unit) with a volume of 1000 mL (900 mL is used actively) was connected to the water bath (water circulator) for the mesophilic conditions (35±1 °C temperature). Providing air-tight the mechanic mixer working at 40 rpm that was connected to the glass reactor. Before the fermentation 5 bar nitrogen gas was pressurized to the system for 2 minutes so as to provide oxygen-free media The composition of the biogas obtained during 2, 4, 8, 12 and 24 hours in the experiments that were determined as Methane (CH4), Carbon Dioxide (CO2), Oxygen (O2), Hydrogen (H2) and Hydrogen Sulfide (H2S) and the ratio of the biogas was 86% during the 24 hours co-digestion period. The highest methane production rate was achieved in the first 8 hours, and it was determined that methane (biogas) production was possible via anaerobic co-digestion from organic wastes. By using the RSM method, the effect of the mentioned organic wastes and time variables on the formation of methane gas was investigated. The slurry remaining in the reactor after anaerobic co-digestion is called fermented fertilizer. Chemical analyzes (such as pH, and elemental composition) of fermented fertilizer and the agricultural soils of Çankırı Province, Eldivan district was conducted and the usage of remaining slurry as fermented fertilizer in agricultural soils is possible due to having a close pH 7,57 value to the pH value (8,033) of the agricultural soils and 4,49 % content of fumic asid that enriches the agicultural soils with organic substances.